Safety device for elevators.



E. E. MOULTON.

SAFETY DEVICE FOR ELEVATORS.

APPLICATION FILED NOV. 27, 1908.

Patented Aug. 17, 1909.

ANDREW a. cnmm 1:0,, PROTO L was E. E. MOULTON.

SAFETY DEVICE FOR ELEVATORS.

. APPLICATION FILED NOV. 27, 190B.

931,21 1, Patented Aug. 17, 1909; ZSHEETS-SHEET 2.

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SAFETY DEVICE FOR ELEVATORS.

Specification of Letters Patent.

Application filed November 2'7, 1908.

Patented Aug. 17', 1909.

Serial No. 464,578.

T 0 all whom it may concern:

Be it known that I, ERNEST E. MoUL'roN, a citizen of the United States,residing at Cleveland, in the county of Cuyahoga, State of Ohio, haveinvented certain new and useful Improvements in Safety Devices forElevators; and I do hereby declare the following to be a full, clear,and exact description f the invention, such as will enable othersskilled in the art to whichit appertains to make and use the same.

The invention relates to safety devices for elevators and moreparticularly to the class of safety devices to prevent the accidentaldropping or descending of the elevator cage upon the breaking of itshoisting cable.

The primary object of the invention is the provision of a safety devicefor elevators comprising a pair of spring controlled catch membersautomatically actuated upon the breaking of the lifting cable of theelevator cage to engage stationary racks at opposite sides of theelevator cage to stop or lock the cage to prevent the same from fallingor descending in the well or the like.

Another object of the invention is the provision of a safety device forelevators which is simple in its construction, thoroughly efiicient inoperation and inexpensive in the manufacture.

Vith these and other objects in view the invention consists in theconstruction, combination and arrangement of parts as will behereinafter more fully described and as illustrated in the accompanyingdrawings which disclose the preferred form of embodiment of theinvention. However, it is to be understood that changes, variations andmodifications may be made such as come properly within the scope of theclaim hereunto appended withoutdeparting from the spirit of theinvention.

In the drawings: Figure 1 is a vertical section taken through a buildingprovided with a well and its elevator cage with the invention appliedthereto and in normal position. Fig. 2 is a similar view with portionsof the same broken away. Fig. 3 is a horizontal sectional view on theline 33 of Fig. 1. Fig. t is a vertical sectional view through the cagewith the safety device in its locked position.

Similar reference characters indicate corresponding parts throughout theseveral views in the drawings.

In the drawings the numeral 7 designates generally the elevator cagehaving a. main platform 8, rising from opposite sides then of arevertical uprights 9 connected at their upper ends by a cross beam 10 andthe said uprights 9 are provided with longitudinal guide grooves 11 intheir outer faces to engage tongues forming guides 12 projectinginwardly from opposite sides of the well or shaft 13 which is of theordinary construct-ion.

Depending centrally from the cross beam 10 of the cage and securedthereto is a tube or cylindrical shell 14 the latter containing atdiametrically opposite points registering elongated slots 15 in whichworks a horizontally disposed bar or plate 16 to which latter isconnected one end of a hoisting cable 17 the latter passing through acentral opening 18 in the cross beam 10 and trained over a pulley 19journaled at the top of the well or shaft 13. This hoisting cable 17 isalso trained over a pulley 20 and has its opposite end connected. to awinding drum 21 the latter when actuated adapted to raise the cage 7 inthe well or shaft and also to permit its descent.

Supported by pivots 22 in the uprights 9 are locking dogs or catchmembers 23 which latter are adapted to be moved into engagement withrack teeth 2 1 formed on the tongues or guides 12 in the well or shaftto prevent the dropping of the cage should the lifting cable becomebroken. The said catch members 23 are formed with inward extensions 25,the latter having rising therefrom centering lugs 26 to form centeringbearings for the lower ends of coiled expansion springs 27 which latterhave their opposite ends resting in recesses 28 formed in the under faceof the cross beam 10 at the top of the elevator cage and these springsare adapted to automatically move the catch members'28 into a lockingposition upon the breaking of the lifting cable.

Interposed between the cross beam 10 and the horizontal bar or plate 16is a coiled main expansion spring 29 one end of which has its bearingagainst the said bar or plate 16 and the other end bearing against theunder face of the cross bar of the elevator cage. The main expansionspring is mounted within the shell or tube 14 and serves to lower thebar or plate 16 to permit positive movement of the catch members 23 uponthe breaking of the hoisting cable.

Adjacent the opening 18 in the cross beam 10 and projecting from theupper face is fixed an eye 30 to which is connected one end of aflexible cable 31 the latter trained over a pulley 32 ournaled adjacentthe pulley 19 and which cable 31 is also trained over a further pulley33 and its opposite end is connected to a counter-balance weight 3 1,which latter approximately weighs eight hundred pounds while the weightof the cage 7 is one thousand pounds thereby making it easy for a singleperson to operate the elevator.

Normally due to the taut condition of the lifting cable 17 the plate orbar 16 is held in a position to engage the inner extremities of theextensions 25 of the catch members to 'maintain the expansion springs 27retracted so as to hold the catch members 23 disengaged from the rackteeth 24: of the guides in the well or shaft. 'Upon the breaking of thelifting or hoisting cable 17 the main expansion spring 29 will move thebar or plate 16 in an opposite direction to permit the expansion of thesprings 27 so as to throw the catch members 23 into locked engagementwith the rack teeth 24 of the guides and thereby prevent the lowering oraccidental descent of the cage 7 within the well or shaft.

Vhat is claimed is- The combination with rack guides, of an elevatorcage having vertical uprights, containing longitudinal grooves engagingthe rack guides, a cross beam connecting the upper ends of the uprights,a cylindrical shell depending centrally from the cross beam andcontaining diametrically opposite slots, catch members having innerextensions, pivotally connected to the uprights, tension springsinterposed between the extensions and the cross beam, a cross memberworking in the slots contained in the shell, a hoisting cable connectedto the member and adapted to retract the tension springs acting upon theextensions, and expansion means interposed between the cross member andthe cross beam and adapted to move the said member upon the breaking ofthe lifting cable to permit automatic engagement of the catch memberswith the guide racks.

In testimony whereof, I aflix my signature, in presence of twowitnesses.

ERNEST E. MOULTON. Witnesses:

F. E. NIOHOLLS, J. WV. DENMAN.

